ESAS 9-2

The center of gravity of a log, 10 ft long and weighing 100 lb, is 4 ft from one end of the log. It is to be carried by two men. If one is at the heavy end, how far from the other end does the second man have to hold the log if each is to carry 50 lb?

• 2 ft

• 4 ft

• 5 ft

• 6 ft

For a rectangular section of breadth "b" and depth "h" the section modulus is given by:

• Z = bh³/12

• Z = bh³/6

• Z = bh²/12

• Z = bh²/6

Ideal fluid has:

• no surface tension

• no surface tension, no viscosity

• no surface tension, no viscosity and no compressibility

• surface tension, viscosity and compressibility

A thin hollow sphere of radius 10 in and thickness 0.1 in is subjected to an internal pressure of 100 psig. The maximum normal stress on an element of the sphere is

• 5,000 psi

• 10,000 psi

• 25,000 psi

• 20,000 psi

The area of the shear diagram of a beam between any two points on the beam is equal to the

• Change in shear between the two points

• Total shear beyond the two points

• Average moment between the two points

• Change in moment between the two points

Carbon dioxide "snow" from a fire extinguisher puts out a fire because it

• lowers the kindling temperature of the material

• displaces the supply of oxygen

• raises the kindling temperature of the material

• cools the material below its kindling temperature

The rocks generally used for roofing is,

• granite

• basalt

• slate

• trap

During a refrigeration cycle, heat is rejected in a:

• evaporator

• condenser

• compressor

• expansion valve

A 20-g piece of aluminum (c = 0.21 cal/g-deg C) at 90 deg C is dropped into a cavity in a large block of ice at 0 deg C. How much ice does the aluminum melt?

• 6.3 g

• 3.6 g

• 7.4 g

• 4.7 g

Stainless steel resists corrosion due to

• carbon

• sulfur

• chromium

• vanadium